Mery Vaca is a respected journalist who focuses on Bolivia. The page is in Spanish, but it appears to be grammatically correct and BBC Mundo is usually very high quality. She quotes activists in the issue and various sources she uses for her statistics. It was last edited on September 29, 2010. This page provides facts and focuses on a single organization for its information. It has a wide scope of the information it provides.
This article does not site specific authors but it does have places to email the author and contact the site's administrators. Again, the site is in Spanish, but the sources are reliable (WHO, Intervida.org) and the information is confirmed in other sites I've seen. There are some Google ads on the site, most likely to support its upkeeping. The article was last edited on January 24, 2007 and has not been updated since. The site is written for women, so it is focused on the Intervida organization to help women and has some scary statistics to tell women to be careful.
This article written by Abigail Griffith, a research associate for the Council on Hemispheric Affairs, an established organization. It presents accurate information on the status of indigenous people in several countries in Latin America. Published recently on June 21, 2010, the article uses facts as well as statistics from the past and present, that are correctly cited with it, as evidence. It is an excellent source, providing in-depth analysis on the topic.